Think clearly.
Build freely.
Adapt faster.
The psychology of doing your best work while everything changes. Weekly essays on Substack, and two decades of writing by Donn Felker right here.
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What I'm building
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The Freelance Playbook
The field guide I wish I'd had on day one: how to land clients, price with nerve, work with AI, and build independent work that compounds.
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ForTimeiOS & Android
A free workout timer for CrossFit, HIIT, and functional fitness. Tabata, EMOM, intervals, and a full gym clock, built under my Knurl Fitness brand.
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Listomo
Email marketing software that doesn't cost an arm and a leg. I got tired of spending $400 to $600 a month on email marketing software, so I built my own and cut the cost by 10x.
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All articles
I Built a Prompt Injection Guard in 48 Hours. One Sentence in Spanish Killed It.
On analogies, dead projects, and questions asked too late.
2026.07.23Read on Substack →
Reducing OpenClaw Token Costs with claw-llm-router
Right model, right time. Save tokens.
2026.02.25Read →
The Passive AI Learning Stack That Changed the Way I Learn
Learn more with less effort.
2026.02.08Read →
Learn Agentic Coding in 2 Days (and unlock a decade of productivity)
Evolving into an Agentic Coding Architect
2025.11.10Read →
The Single Most Important Thing You Need as a One-Person Business to Guarantee You Get Paid
Get paid or go broke.
2025.08.06Read →
Vibe Coding with AI and the Future of Software
Software’s Industrial Revolution Moment
2025.04.16Read →
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